Abrasive substances for cutting, smoothing and polishing the surface of hard materials have developed their own niche in industry. Materials known for their high degree of hardness, such as diamonds and CBN, have long been used as the cutting edge of tools in grinding, sawing, lapping, machining and drilling. Typically, the working surface of a tool made of steel or other metallic substrate is coated with a layer of the harder, more abrasion-resistant material.
In one application, a titanium nitride coating is applied over conventional CBN tools by arc physical-vapor-deposition. The titanium nitride stabilizes and reinforces the existing bond between the CBN and the core, resulting in a grinding tool with greater efficiency and longer life. Specific operating conditions, however, are required during the deposition process in order to ensure the proper level of adhesion of the titanium nitride. See U.S. Pat. No. 5,139,537.
A need still remains for even more improved grinding wheels. More sophisticated metals and a demand for even more precise grinding require better wheels.